title: Case-control study of childhood leukaemia and cancer in Scotland: findings for neonatal intramuscular vitamin K.
abstract: OBJECTIVE
  To test the hypothesis of an association between neonatal intramuscular vitamin K and childhood leukaemia and other cancers.
  
  
  METHODS
  Population based case-control study with data abstracted from hospital records.
  
  
  METHODS
  Scotland.
  
  
  METHODS
  Children aged 0-14 years resident in Scotland from 1991-4 and diagnosed with leukaemia (150), lymphomas (46), central nervous system tumours (79), a range of other solid tumours (142), and a subset of acute lymphoblastic leukaemia (129). Controls were 777 children matched for age and sex, providing 417 matched sets (360 triplets and 57 pairs) for analysis.
  
  
  METHODS
  Odds ratios for the risk of childhood leukaemia and cancer and intramuscular vitamin K versus a combined group of oral doses, none, and no record. Results are given for information recorded in medical notes and data supplemented by hospital policy.
  
  
  RESULTS
  Odds ratios based on medical record abstractions showed no significant positive association for leukaemias (odds ratio 1.30; 95% confidence interval 0.83 to 2.03), acute lymphoblastic leukaemia (1.21; 0.74 to 1.97), lymphomas (1.06; 0.46 to 2.42), central nervous system tumours (0.74; 0.40 to 1.34), and other solid tumours (0.59; 0.37 to 0.96). There was no association with acute lymphoblastic leukaemia in children aged 1 to 6 years. Imputation of exposure from hospital policy gave similar results. Adjustment for deprivation and type of delivery moved risk estimates closer to unity for all major diagnostic groups.
  
  
  CONCLUSIONS
  The observation of an increased risk of childhood leukaemia and cancer associated with intramuscular vitamin K is not confirmed by this independent population based study.
authors.affiliation: Information and Statistics Division, Common Services Agency for the National Health Service in Scotland, Edinburgh. p.a.mckinney@leeds.ac.uk
authors.forename: P A
authors.initials: PA
authors.lastname: McKinney
authors.forename: E
authors.initials: E
authors.lastname: Juszczak
authors.forename: E
authors.initials: E
authors.lastname: Findlay
authors.forename: K
authors.initials: K
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007273:Injections, Intramuscular; D007938:Leukemia / Q000139:chemically induced / Q000453:epidemiology; D009369:Neoplasms / Q000139:chemically induced* / Q000453:epidemiology; D016017:Odds Ratio; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000139:chemically induced; D012606:Scotland / Q000453:epidemiology; D014812:Vitamin K / Q000008:administration & dosage / Q000009:adverse effects*; D014813:Vitamin K Deficiency / Q000517:prevention & control
chemical_list: D014812:Vitamin K